2. Characteristics of Testable Software
o Operable
o The better it works (i.e., better quality), the easier it
is to test
o Observable
o Incorrect output is easily identified; internal errors
are automatically detected
o Controllable
o The states and variables of the software can be
controlled directly by the tester
o Decomposable
o The software is built from independent modules
that can be tested independently
3. Characteristics of Testable Software
o Simple
o The program should exhibit functional, structural,
and code simplicity
o Stable
o Changes to the software during testing are
infrequent and do not invalidate existing tests
o Understandable
o The architectural design is well understood;
documentation is available and organized
4. Test Characteristics
o A good test has a high probability of
finding an error
o The tester must understand the software and how
it might fail
o A good test is not redundant
o Testing time is limited; one test should not serve
the same purpose as another test
o A good test should be “best of breed”
o Tests that have the highest likelihood of
uncovering a whole class of errors should be used
o A good test should be neither too
simple nor too complex
o Each test should be executed separately
5. Testing Techniques
o White Box Testing
o Testing of a software solution’s internal
coding and infrastructure.
o Black Box Testing
o Functionality of the Software-Under-Test
(SUT) is checked without looking at the
internal coding and structure.
6. White Box Testing
o Developers get involved.
o Knowing the internal workings of
a product, all the internal
operations are tested according
to specifications and all internal
components are exercised.
o Logical paths through the
software are tested.
7. White Box Testing
o Other names:
o Clear Box Testing
o Structural Box Testing
o Open Box Testing
o Opaque (or Glass) Box Testing
8. Types of White Box Testing
o UNIT Testing
o INTEGRATION Testing
9. Unit Testing
o A ‘unit’ is the smallest part in the
application where the
developers test the individual
units of source code.
o Its a verification and validation
methodology where the
developers test the individual
units of source code.
o These tests are conducted during
development.
10. Unit Testing
o There are 2 ways of doing “Unit
Test” in .NET
o Visual Studio Unit Test Facility
o In-Built
o Third-Party Software (Not Recommended)
o NUnit
11. Types of Unit Tests
o Basically 3 types:
o Execution Testing:
oAgain 3 types:
o Conditional Coverage:
o Conditional Statements like IF-ELSE are
tested.
o Loops Coverage:
o Loops like FOR,WHILE,DO-WHILE are
tested.
o Program Technique Testing:
o Test to optimize the code (minimum
number of lines).
12. Types of Unit Tests
o Operational Testing:
oCode should execute on customer
expected Operating System.
o Mutation Testing:
oIntentionally try to bring errors in
program execution to increase
efficiency.
15. Integration Testing
o Check all the modules are
working with each other as a
whole or not.
o There are 2 approaches in
Integration Testing:
o TOP DOWN Approach
o BOTTOM UP Approach
16. Top Down Approach
o Main Module is ready and Sub-
Module is under development.
o Ex: “Log-in” is Ready and “Register” is under
development.
o Temporary Program (called as
“STUBS” in this approach) are like
alternatives which takes the
module under development, so
that testing activity of the main
module, or the module which is
ready, can be done.
17. Bottom Up Approach
o Main module is under
development and Sub-Module is
ready.
o “Log-in” is under development and “Register” is
ready.
o Temporary Program (called as
“DRIVERS” in this approach) are
like alternatives which takes the
module under development and
the testing activity of the module
which is ready, is done.
18. Black Box Testing
o Testers get involved.
o Knowing the specified function
that a product has been
designed to perform, testing is
done so as to see if that function
is fully operational and error free.
o Not concerned with internal
logical structure of the software.
o Includes tests that are conducted
at the software interface.
19. Black Box Testing
o Other names:
o Closed Box Testing
o Functionality Testing
o Behavioral Testing
o Test is done just by knowing the inputs
and outputs without knowing their
internal code implementation.
BLACK BOXInput Output
20. Types of Black Box Testing
o Functional Testing:
o Related to functional requirements of the
system.
o Non-Functional Testing:
o Not related to testing of a specific
functionality but non-functional
requirements such as performance,
scalability, usability.
o Regression Testing:
o Done after code fixes, upgrades or any
other system maintenance to check the
new code has not affected the existing
code.
